The Cassio 330 can carry a pilot and five passengers up to 93 mi. with electric propulsion, or up to 745 mi. with hybrid propulsion.
French startup VoltAero has confirmed that its hybrid-electric Cassio 330 general aviation aircraft remains on track for assembly by the end of 2023, and first flight early next year.
The Cassio 330 features a 330 kW electric-parallel hybrid propulsion system built around a Kawasaki piston engine, with an electric motor from Safran and a battery from Electric Power Systems (EPS). The integrated hybrid module drives a single pusher propeller via a gearbox.
The clean-sheet Cassio 330 is designed to carry a pilot and five passengers, or 900 lbs. of cargo, up to 93 mi. using all electric propulsion, or up to 745 mi. using hybrid propulsion. It will be the first of a family of three planned aircraft from VoltAero, in addition to the six-passenger Cassio 480 and 12-passenger Cassio 600, the latter of which will be powered by a six-cylinder piston engine currently under development by Kawasaki.
Before the first Cassio 330 can fly in its electric-parallel hybrid configuration, VoltAero plans to fly its prototype aircraft powered solely with the four-cylinder Kawasaki internal combustion engine, a specially-modified version of the engine that powers the Kawasaki Ninja H2R motorcycle. The four-cylinder piston engine weighs 165 lb. and will produce 150 kW of power, according to the company.
“We will not go directly to hybrid-electric because we want to validate the thermal engine within this configuration first,” Botti tells Aviation Week Network. “Once we have finished the campaign of validation of the Kawasaki engine using this structure, we will insert [Safran] electric motor and [EPS] batteries and then validate the hybrid configuration. We’re doing it step-by-step, to keep the process of certification as simple as possible for EASA.”
The first prototype production-configuration Cassio 330—dubbed the Cassio 21-X—will feature optimized aerodynamics compared to the mockup version that was unveiled at the Paris Air Show in June, including a new high-torque, low-noise propeller from Duc Helice designed specifically for the Cassio, according to Botti. The aircraft will also integrate the 41-kWh battery from EPS, whereas the Cassio S testbed that recently flew on 100% sustainable aviation fuel included a battery developed in-house by the company.
The Cassio 330 is capable of performing takeoff, climbs and landing using its electric propulsion system, while the combustion engine functions as a range-extender and recharges the battery in flight.
The aircraft's structure is made of aluminum, which Botti says is very favorable for protection of passengers from lightning strikes; isolation for electromagnetic interference and electromagnetic compatibility; and recylability, especially as compared to composites.
VoltAero’s Cassio S testbed—a modified Cessna 337 Skymaster—earlier in September completed a 1-hr. test flight powered entirely by Excellium Racing 100, an SP98-type higher-octane unleaded fuel provided by TotalEnergies. When combined with the Cassio’s hybrid architecture, Botti says the test flight demonstrated an 80-85% total reduction in carbon dioxide emissions.
Additionally, VoltAero plans to conduct test flights using liquid hydrogen in 2024 with the prototype Cassio 330. Botti says that he hopes to offer customers a hydrogen-capable Cassio variant equipped with liquid hydrogen storage tanks, which he believes is a more realistic near-term solution than hydrogen-electric fuel cells.
“A fuel cell is not going to be any better than what a heavy thermal engine can do today … when you start to carry a lot of people, it’s almost mission impossible compared to a turbine,” he says.
The Cassio is being designed with an easily-customizable cabin that can accommodate four primary use cases: regional passenger transportation; cargo and logistics; medevac; and mobility services for handicapped passengers.
Botti says the company is aiming for realistic operating cost savings of 34% compared to the similarly-sized Cirrus SR22. “We are not promising the moon like some others are saying, but we are promising something that can actually be achieved with technology that is available today.”
The company is targeting EASA CS-23 certification of the Cassio 330 in 2024, with the larger variants to follow sometime afterward. The certification process will also involve the French civil aviation regulator DGAC, according to Botti.
